What Controls Tropical Cyclone Size and Intensity?
Yuqing Wang, J. Atmos. Sci., in press
While there is much variability from storm to storm, there is a systematic geographical
dependence in tropical cyclone (TC) size and intensity, with large TCs dominant over the western
North Pacific and smaller TCs appearing in the central North Pacific. A study using the IPRC
nonhydrostatic limited area model has implicated the interaction of the central storm with outer
rainbands as critical to determine TC size and intensity. The left panel shows rainfall rates (mm/hr)
after 120 hours of simulation in a control run. The other panels show results from runs in which
the outer rainbands have been suppressed (center) or enhanced (right) by changing the latent
heating rates in the region beyond 50 km from the storm center. In the central Pacific the outer
rainband development may be suppressed by the dryness of the air above the boundary layer,
leading to the intense and very compact TCs characteristic of this area.